Analysis of all-optical switching in periodically poled LiNbO3 waveguide

The characterization of all-optical switching based on cascaded second-order nonlinearity of sum-frequency generation (SFG) and differential frequency generation (DFG) in periodically poled lithium niobate (PPLN) waveguide was analyzed theoretically. The small signal solution of the couple mode equation was given at phase matched firstly. Then based on solving the couple mode equation numerically, the dependence of the signal power on the gate power was given under different phase dismatch conditions. Finally, the dependence of the tolerance of the grating period, the crystal temperature and the gate power on the interaction length and the crystal temperature were analyzed.